Physics P1 - Longitudinal & Transverse waves

What is a transverse wave?

It is the oscillation of particles at right angles to the direction of energy transfer.

What are examples of transverse waves?

Electromagnetic waves.

What speed do electromagnetic waves travel in a vacuum?

3E8 ms^-1

How can a transverse wave be represented by a slinky?

Shaking the slinky vertically.

What is a longitudinal wave?

It is the oscillation of particles which are parallel to the direction of energy transfer.

What are the main parts of a longitudinal wave?

Compressions and rarefaction.

Can longitudinal waves travel in a vacuum?

No, as they won't have a medium to transfer energy through.

What is an example of a longitudinal wave?

Sound.

How would you use a slinky to represent a longitudinal wave?

Pushing a slinky horizontally.

How many planes can a polarised wave oscillate in?

One.

What types of waves can be polarised?

Only transverse.

What does polarisation provide evidence for?

The nature of transverse waves because it can only occur if a wave's oscillations are perpendicular to its direction of travel.

What is an example of an application of polarisation?

Polaroid sunglasses or TV and radio signals.

How do polaroid glasses work?

They reduce glare by blocking partially polarised light reflected from water and tarmac, as the filter only allows oscillations in the plane of the filter. Overall, this makes it easier to see.

How is polarisation used in TV and radio signals?

They are usually plane-polarised by the orientation of the rods on the transmitting aerial, so the receiving aerial must be aligned in the same plane of polarisation to receive the signal at full strength.